Aircraft retractable and steerable nose-wheel and tail-wheel mounting



Sept. 15, 1953 R. c. CUSSONS 2,652,214

AIRCRAFT RETRACTABLE AND STEERABLE NOSE-WHEEL AND TAIL-WHEEL. Filed June 15 1951 MOUNTINGS 2 Sheets-Sheet 1 ATTORNEY R. c. cussoNs 2,652,214 AIRCRAFT RETRACTABLE AND STEERABLE NQSE-WHEEL AND TAIL-WHEEL MOUNTINGS Filed June 15 1951 2 Sheets-Sheet 2' Inventor 10M 0. (ass-ans Patented Sept. 15, 1953 AIRCRAFT RETRACTABLE AND STEERABLE -WHEEL MOUNT- N USE-WHEEL AND TAI ING Richard C. signor to ham, England Cussons,

Cheltenham, England, as- Dowty Equipment Limited, Chelten- Application June 15, 1951, Serial No. 231,847 In Great Britain May 11, 1950 1 Claim. (Cl. 24450) the steerable column itself to column 32 into self-centering and its valve 3| will serve connection has been broken, for example, during retraction of the landing wheel mounting. In the example herein illustrated, there is receiving folds may accor n y e mpl r and l ghter I5 in the spring I 4. The spring I4 is shaped The se f-c n means ay comprise a beyond the folds I5 to embrace also an abutment small fluid pressure opera ed jack, a n r I6 WhlCh is fixed to the retractable but noncam and follower mechanism. rotatable casing 33 of the nose-wheel mounting,

An aircraft retractable and steerable noseof which the fork I1, indicated in Figure 2 by wheel or tail-wheel mounted incorporating selfdot-and-dash lines, is a part When the arm I2 centering means in accordance with the invention is turned with the spindle II in either direction will now be described by way of example with bears against the corresponding end of the reference to the accompanying somewhat diaspring I4 whilst the other end of the spring regrammatic drawings. mains in engagement with the fixed abutment In the drawings, Figure 1 illustrates the com- I6 The spring I4 is therefore further stressed plete retractable steering wheel mount, someduring turning of the spindle I I to tend to rewhat diagrammatically, and Figure 2 is a diaturn the spindle II into its normal angular posigrammatic isometric view of the upper part tion at wh1ch the spring engages both sides of thereof with which the present invention is conthe fixed abutment I6, as seen in the drawing cerned, some of the vertical dimensions being The retractable part of the casing 33 in which the exaggerated for clearness. A typical steering steerable column is journalled is retractable motor servo control and follow-up mechanism about a pair of stub shafts received in ournal of the sort with which this invention is conbearings I8 at the upper part of the mounting cerned is fully described and illustrated in the At the upper end of the spindle II there is prospecification of Dowty Patent No. 2,543,233 dated vided a transverse bar l9 which is fixed to turn February 27, 1951, and is less fully illustrated in as one with the spindle. The bar I9 is fitted Figure 1 of this application. When the spindle with adjustable studs 20 having heads 2! which II at the upper terminus of the servo control engage a bar 22 on a spindle 23 which is disposed and follow-up mechanism designated generally above and co-axially in line with the spindle II by the numeral I0 is turned under the control The spindle 23 is ournalled in a bracket 24 which of the pilot to effect steering of the column, a is secured to a fixed part of the aircraft structure servo valve 30 of the hydraulic steering motor The spindle 23 can be turned under the control system is displaced to initiate operation of the of the pilot through the push and pull rod 25 steering motor 3I to turn the steerable column which is pivoted to an arm 26 fast upon the 32 which, in turning, reacts upon the follow-up spindle 23. When the nose wheel mounting 1S linkage of the mechanism to return the servo swung into its fully lowered position after having valve element 30 to its neutral position, all, as been retracted the heads 2| of the studs 20 both described more fully in the prior Dowty patent engage the bar 22 so that the pilot has direct referred to. Whereas in prior known construccontrol over the turning of the spindle II just tions,self-centering means operates directly upon 5 as if the spindles 23 and II were extensions one of the other. When the mounting swings up during the process of retracting the nose-wheel, the bar 19 and the studs 20 move away from the bar 22 which latter remains with the spindle 23 in the fixed bracket 24. If, prior to retraction, the steerable column 32 of the mounting had been turned into a steering attitude out of the foreand-aft alignment of the wheel, the bar 22 and with it the bar 19 and spindle ll would be turned to some extent in either one direction, and the self-centering spring [4 would be opened and consequently given an extra stress. Directly the mounting 33, H swings in the act of retraction, the bar ill will move out of contact with the bar 22, so that the spring M is able to return the spindle H into its angular position corresponding with fore-and-aft alignment of the landing wheel. The return of the spindle H will operate the steering motor through its servo control and follow-up mechanism 10, and the steering motor 3!, controlled by mechanism to will thus supply the power necessary to return the wheel into the desired alignment.

During normal steering, the effect of the selfcenter-ing spring I4 is overcome by the pilot exercising control on the spindle H through the driving connection 22 and I9 between th spindle 23 and the spindle II.

It will be understood that other forms of selfcentering means may be employedinstead of the 0 spring shown in the drawing, but whatever form is used, the fact that the self-centering means operates upon a spindle of the servo control and not upon the steerable column itself,

it follows that the. self-centering means can be simpler: and lighter than if it were to operate directly upon the steerable column.

I claim:

An aircraft-retractable and steerable wheel mounting comprising a non-rotatable casing adapted to be hingedly connected to an aircraft for movement between a retracted position and an extended position, a wheel-supporting column mounted rotatable about its axis in said casing, servomotor means mounted on said casing, said servomotor means including a rotatable servocontrol spindle and an associated steering motor operatively connected to said wheel-supporting column to maintain positional correspondence or said column with said servo-control spindle, centralizing spring means acting between the casing and the servo-control spindle to restore it to a rest position corresponding to the central position of the wheel-supporting column, a steering spindle mounted on the aircraft so as to lie co-axial with the servo-control spindle in the extended position of the wheel mounting, and a separable transmission coupling consisting of complementary parts fixed respectively to the servo-control spindle and to the steering spindle, said complementary parts being adapted to coact when the wheel mounting is extended for transmitting steering control to the servomotor means in opposition to the loading of said centralizing spring means, and to separate when the wheel mounting is retracted for subjecting the servomotor means solely to the influence of the centralizing spring means.

RICHARD C. CUSSONS.

References Cited in the file of this patent UNITED STATES PATENTS 

